Primary battery.



UNITED STATES Patented Augusti9, 1904.

PATENT OFFICE,

THOMAS A. EDISON, OF LLEVVELLYN PARK, NEW JERSEY, ASSIGNOR TO EDISONMANUFACTURING COMPANY, OF ORANGE, NEW JERSEY, A

CORPORATION OF NEW JERSEY.

PRIMARY BATTERY.

SPECIFICATION forming part of Letters Patent No. 766,815, dated August9, 1904.

Application filed November 18, 1903. Serial No. 181,591. (No model.)

To all, whom it may concern:

Be it known that I, TI-IoMAs ALvA EmsoN, of Llewellyn Park, Orange, .inthe county of Essex and State of New Jersey, have invented certainImprovements for Primary Batteries, of which the following is adescription.

My invention relates to the manufacture of copper-oxid electrodes forprimary batteries, preferably of the Lalande type, wherein copper oxidis opposed to metallic Zinc in an alkaline solution The object of myinvention is to produce a copper-oxid electrode of superior quality andat a moderate cost.

In the use of batteries of the Lalande type on discharge the copper oXidis reduced to the metallic state and the zinc oxidized. The cell doesnot reach its normal discharge rate until the surface of the negativeelectrode is completely reduced to the metallic state, so that it is thepractice in the art to preliminarily reduce the surface of theseelectrodes before assembling them, so as to save the time required toeffect this reduction in the cell itself.

- I find that very good results can be secured by dispensing with thepreliminary reduction of the copper oXid and substituting therefor atreatment With ordinary red oXid of copper applied in any suitablewayas, for example, of rubbing the red oxid onthe surface of theelectrode. The electrode is more or less porous, so that the particlesof red oXid adhere very tenaeiously to the surface. A copperoxidelectrode so treated when properly connected up in a cell gives a verysatisfactory discharge rate, and since the red oxid is readily reduciblethe surface reduction to the me tallic state progresses rapidly, so thatthe cell quickly reaches its full discharge rate. The copper-oxideleetrod es which are thus treated can be obtained in any way; but Iprefer to make them by treating precipitated hydroxid of copper withhypoehlorite of sodium, thereby produeing an excessively finely dividedblack oxid of copper, which is then dried,

moistened witha solution of sodium, and' teries comprising a compressedmass of black oXid of copper, carrying a film of red oxid of copper onits surface, substantially as set forth.

3. A negative electrode for primary batteries comprising a porouscompressed mass of black oxid of copper. and finely-divided red oXid ofcopper applied to the porous surface,

substantially as set forth.

This specification signed and witnessed this 16th day of November, 1903.

THOMAS A. Emson.

l/Vitnesses:

FRANK L. DYER, HARRY G. WALTERS;

